package com.ngds.library.downloadcenter;

import android.content.ContentResolver;
import android.content.ContentUris;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.CursorWrapper;
import android.net.Uri;
import android.os.Environment;
import android.os.ParcelFileDescriptor;
import android.provider.Settings;
import android.provider.Settings.SettingNotFoundException;
import android.text.TextUtils;
import android.util.Pair;

import java.io.File;
import java.io.FileNotFoundException;
import java.util.ArrayList;
import java.util.List;

/**
 * The download manager is a system service that handles long-running HTTP
 * downloads. Clients may request that a URI be downloaded to a particular
 * destination file. The download manager will conduct the download in the
 * background, taking care of HTTP interactions and retrying downloads after
 * failures or across connectivity changes and system reboots.
 * <p/>
 * Instances of this class should be obtained through
 * {@link android.content.Context#getSystemService(String)} by passing
 * {@link android.content.Context#DOWNLOAD_SERVICE}.
 * <p/>
 * Apps that request downloads through this API should register a broadcast
 * receiver for {@link #ACTION_NOTIFICATION_CLICKED} to appropriately handle
 * when the user clicks on a running download in a notification or from the
 * downloads UI.
 */
public class AppDownloadManager {

    /**
     * An identifier for a particular download, unique across the system.
     * Clients use this ID to make subsequent calls related to the download.
     */
    public final static String COLUMN_ID = Downloads.Impl._ID;

    /**
     * The client-supplied title for this download. This will be displayed in
     * system notifications. Defaults to the empty string.
     */
    public final static String COLUMN_TITLE = Downloads.Impl.COLUMN_TITLE;
    public final static String COLUMN_IS_START_DIRECTLY = Downloads.Impl.COLUMN_IS_START_DIRETLY;

    /**
     * The client-supplied description of this download. This will be displayed
     * in system notifications. Defaults to the empty string.
     */
    public final static String COLUMN_DESCRIPTION = Downloads.Impl.COLUMN_DESCRIPTION;

    /**
     * URI to be downloaded.
     */
    public final static String COLUMN_URI = Downloads.Impl.COLUMN_URI;

    /**
     * Internet Media Type of the downloaded file. If no value is provided upon
     * creation, this will initially be null and will be filled in based on the
     * server's response once the download has started.
     *
     * @see <a href="http://www.ietf.org/rfc/rfc1590.txt">RFC 1590, defining
     * Media Types</a>
     */
    public final static String COLUMN_MEDIA_TYPE = "media_type";

    /**
     * Total size of the download in bytes. This will initially be -1 and will
     * be filled in once the download starts.
     */
    public final static String COLUMN_TOTAL_SIZE_BYTES = "total_size";

    /**
     * Uri where downloaded file will be stored. If a destination is supplied by
     * client, that URI will be used here. Otherwise, the value will initially
     * be null and will be filled in with a generated URI once the download has
     * started.
     */
    public final static String COLUMN_LOCAL_URI = "local_uri";

    /**
     * The pathname of the file where the download is stored.
     */
    public final static String COLUMN_LOCAL_FILENAME = "local_filename";

    /**
     * Current status of the download, as one of the STATUS_* constants.
     */
    public final static String COLUMN_STATUS = Downloads.Impl.COLUMN_STATUS;

    /**
     * Provides more detail on the status of the download. Its meaning depends
     * on the value of {@link #COLUMN_STATUS}.
     * <p/>
     * When {@link #COLUMN_STATUS} is {@link #STATUS_FAILED}, this indicates the
     * type of error that occurred. If an HTTP error occurred, this will hold
     * the HTTP status code as defined in RFC 2616. Otherwise, it will hold one
     * of the ERROR_* constants.
     * <p/>
     * When {@link #COLUMN_STATUS} is {@link #STATUS_PAUSED}, this indicates why
     * the download is paused. It will hold one of the PAUSED_* constants.
     * <p/>
     * If {@link #COLUMN_STATUS} is neither {@link #STATUS_FAILED} nor
     * {@link #STATUS_PAUSED}, this column's value is undefined.
     *
     * @see <a
     * href="http://www.w3.org/Protocols/rfc2616/rfc2616-sec6.html#sec6.1.1">RFC
     * 2616 status codes</a>
     */
    public final static String COLUMN_REASON = "reason";

    /**
     * Number of bytes download so far.
     */
    public final static String COLUMN_BYTES_DOWNLOADED_SO_FAR = "bytes_so_far";

    /**
     * Timestamp when the download was last modified, in
     * {@link System#currentTimeMillis System.currentTimeMillis()} (wall clock
     * time in UTC).
     */
    public final static String COLUMN_LAST_MODIFIED_TIMESTAMP = "last_modified_timestamp";

    /**
     * The URI to the corresponding entry in MediaProvider for this downloaded
     * entry. It is used to delete the entries from MediaProvider database when
     * it is deleted from the downloaded list.
     */
    public static final String COLUMN_MEDIAPROVIDER_URI = Downloads.Impl.COLUMN_MEDIAPROVIDER_URI;


    /**
     * Value of {@link #COLUMN_STATUS} when the download is waiting to start.
     */
    public final static int STATUS_PENDING = 1 << 0;

    /**
     * Value of {@link #COLUMN_STATUS} when the download is currently running.
     */
    public final static int STATUS_RUNNING = 1 << 1;

    /**
     * Value of {@link #COLUMN_STATUS} when the download is waiting to retry or
     * resume.
     */
    public final static int STATUS_PAUSED = 1 << 2;

    /**
     * Value of {@link #COLUMN_STATUS} when the download has successfully
     * completed.
     */
    public final static int STATUS_SUCCESSFUL = 1 << 3;

    /**
     * Value of {@link #COLUMN_STATUS} when the download has failed (and will
     * not be retried).
     */
    public final static int STATUS_FAILED = 1 << 4;

    /**
     * Value of COLUMN_ERROR_CODE when the download has completed with an error
     * that doesn't fit under any other error code.
     */
    public final static int ERROR_UNKNOWN = 1000;

    /**
     * Value of {@link #COLUMN_REASON} when a storage issue arises which doesn't
     * fit under any other error code. Use the more specific
     * {@link #ERROR_INSUFFICIENT_SPACE} and {@link #ERROR_DEVICE_NOT_FOUND}
     * when appropriate.
     */
    public final static int ERROR_FILE_ERROR = 1001;

    /**
     * Value of {@link #COLUMN_REASON} when an HTTP code was received that
     * download manager can't handle.
     */
    public final static int ERROR_UNHANDLED_HTTP_CODE = 1002;

    /**
     * Value of {@link #COLUMN_REASON} when an error receiving or processing
     * data occurred at the HTTP level.
     */
    public final static int ERROR_HTTP_DATA_ERROR = 1004;

    /**
     * Value of {@link #COLUMN_REASON} when there were too many redirects.
     */
    public final static int ERROR_TOO_MANY_REDIRECTS = 1005;

    /**
     * Value of {@link #COLUMN_REASON} when there was insufficient storage
     * space. Typically, this is because the SD card is full.
     */
    public final static int ERROR_INSUFFICIENT_SPACE = 1006;

    /**
     * Value of {@link #COLUMN_REASON} when no external storage device was
     * found. Typically, this is because the SD card is not mounted.
     */
    public final static int ERROR_DEVICE_NOT_FOUND = 1007;

    /**
     * Value of {@link #COLUMN_REASON} when some possibly transient error
     * occurred but we can't resume the download.
     */
    public final static int ERROR_CANNOT_RESUME = 1008;

    /**
     * Value of {@link #COLUMN_REASON} when the requested destination file
     * already exists (the download manager will not overwrite an existing
     * file).
     */
    public final static int ERROR_FILE_ALREADY_EXISTS = 1009;

    /**
     * Value of {@link #COLUMN_REASON} when the download has failed because of
     * {@link NetworkPolicyManager} controls on the requesting application.
     *
     * @hide
     */
    public final static int ERROR_BLOCKED = 1010;

    /**
     * Value of {@link #COLUMN_REASON} when the download is paused because some
     * network error occurred and the download manager is waiting before
     * retrying the request.
     */
    public final static int PAUSED_WAITING_TO_RETRY = 1;

    /**
     * Value of {@link #COLUMN_REASON} when the download is waiting for network
     * connectivity to proceed.
     */
    public final static int PAUSED_WAITING_FOR_NETWORK = 2;

    /**
     * Value of {@link #COLUMN_REASON} when the download exceeds a size limit
     * for downloads over the mobile network and the download manager is waiting
     * for a Wi-Fi connection to proceed.
     */
    public final static int PAUSED_QUEUED_FOR_WIFI = 3;

    /**
     * Value of {@link #COLUMN_REASON} when the download is paused for some
     * other reason.
     */
    public final static int PAUSED_UNKNOWN = 4;


    /**
     * columns to request from DownloadProvider.
     *
     * @hide
     */
    public static final String[] UNDERLYING_COLUMNS = new String[] {
        Downloads.Impl._ID,
        Downloads.Impl._DATA + " AS " + COLUMN_LOCAL_FILENAME,
        Downloads.Impl.COLUMN_MEDIAPROVIDER_URI,
        Downloads.Impl.COLUMN_DESTINATION,
        Downloads.Impl.COLUMN_ERROR_MSG,
        Downloads.Impl.COLUMN_TITLE,
        Downloads.Impl.COLUMN_IS_START_DIRETLY,
        Downloads.Impl.COLUMN_DESCRIPTION,
        Downloads.Impl.COLUMN_URI,
        Downloads.Impl.COLUMN_STATUS,
        Downloads.Impl.COLUMN_FILE_NAME_HINT,
        Downloads.Impl.COLUMN_MIME_TYPE + " AS " + COLUMN_MEDIA_TYPE,
        Downloads.Impl.COLUMN_TOTAL_BYTES + " AS "
            + COLUMN_TOTAL_SIZE_BYTES,
        Downloads.Impl.COLUMN_LAST_MODIFICATION + " AS "
            + COLUMN_LAST_MODIFIED_TIMESTAMP,
        Downloads.Impl.COLUMN_CURRENT_BYTES + " AS "
            + COLUMN_BYTES_DOWNLOADED_SO_FAR,
            /*
             * add the following 'computed' columns to the cursor. they are not
			 * 'returned' by the database, but their inclusion eliminates need
			 * to have lot of methods in CursorTranslator
			 */
        "'placeholder' AS " + COLUMN_LOCAL_URI,
        "'placeholder' AS " + COLUMN_REASON};


    /**
     * This class contains all the information necessary to request a new
     * download. The URI is the only required parameter.
     * <p/>
     * Note that the default download destination is a shared volume where the
     * system might delete your file if it needs to reclaim space for system
     * use. If this is a problem, use a location on external storage (see
     * {@link #setDestinationUri(android.net.Uri)}.
     */
    public static class Request {
        /**
         * Bit flag for {@link #setAllowedNetworkTypes} corresponding to
         * {@link android.net.ConnectivityManager#TYPE_MOBILE}.
         */
        public static final int NETWORK_MOBILE = 1 << 0;

        /**
         * Bit flag for {@link #setAllowedNetworkTypes} corresponding to
         * {@link android.net.ConnectivityManager#TYPE_WIFI}.
         */
        public static final int NETWORK_WIFI = 1 << 1;

        private Uri mUri;
        private Uri mDestinationUri;
        private List<Pair<String, String>> mRequestHeaders = new ArrayList<Pair<String, String>>();
        private CharSequence mTitle;
        private CharSequence mDescription;
        private String mMimeType;
        private int mAllowedNetworkTypes = ~0; // default to all network types
        // allowed
        private boolean mIsVisibleInDownloadsUi = true;
        private boolean mScannable = false;
        private boolean mUseSystemCache = false;

        public boolean isStartDirectly() {
            return mIsStartDirectly;
        }

        public void setIsStartDirectly(boolean mIsStartDirectly) {
            this.mIsStartDirectly = mIsStartDirectly;
        }

        /**
         * 是否立即开始（无视线程池限制）
         */
        private boolean mIsStartDirectly;

        /**
         * if a file is designated as a MediaScanner scannable file, the
         * following value is stored in the database column
         * {@link com.ngds.library.downloadcenter.Downloads.Impl#COLUMN_MEDIA_SCANNED}.
         */
        private static final int SCANNABLE_VALUE_YES = 0;
        // value of 1 is stored in the above column by DownloadProvider after it
        // is scanned by
        // MediaScanner
        /**
         * if a file is designated as a file that should not be scanned by
         * MediaScanner, the following value is stored in the database column
         * {@link com.ngds.library.downloadcenter.Downloads.Impl#COLUMN_MEDIA_SCANNED}.
         */
        private static final int SCANNABLE_VALUE_NO = 2;

        /**
         * This download is visible but only shows in the notifications while
         * it's in progress.
         */
        public static final int VISIBILITY_VISIBLE = 0;

        /**
         * This download is visible and shows in the notifications while in
         * progress and after completion.
         */
        public static final int VISIBILITY_VISIBLE_NOTIFY_COMPLETED = 1;

        /**
         * This download doesn't show in the UI or in the notifications.
         */
        public static final int VISIBILITY_HIDDEN = 2;

        /**
         * This download shows in the notifications after completion ONLY. It is
         * usuable only with
         * {@link com.ngds.library.downloadcenter.AppDownloadManager#addCompletedDownload(String, String, boolean, String, String, long, boolean)}
         * .
         */
        public static final int VISIBILITY_VISIBLE_NOTIFY_ONLY_COMPLETION = 3;

        /**
         * can take any of the following values: {@link #VISIBILITY_HIDDEN}
         * {@link #VISIBILITY_VISIBLE_NOTIFY_COMPLETED},
         * {@link #VISIBILITY_VISIBLE},
         * {@link #VISIBILITY_VISIBLE_NOTIFY_ONLY_COMPLETION}
         */
        private int mNotificationVisibility = VISIBILITY_VISIBLE;

        /**
         * @param uri the HTTP URI to download.
         */
        public Request(Uri uri) {
            if (uri == null) {
                throw new NullPointerException();
            }
            String scheme = uri.getScheme();
            if (scheme == null
                || (!scheme.equals("http") && !scheme.equals("https"))) {
                throw new IllegalArgumentException(
                    "Can only download HTTP/HTTPS URIs: " + uri);
            }
            mUri = uri;
        }

        Request(String uriString) {
            mUri = Uri.parse(uriString);
        }

        /**
         * Set the local destination for the downloaded file. Must be a file URI
         * to a path on external storage, and the calling application must have
         * the WRITE_EXTERNAL_STORAGE permission.
         * <p/>
         * The downloaded file is not scanned by MediaScanner. But it can be
         * made scannable by calling {@link #allowScanningByMediaScanner()}.
         * <p/>
         * By default, downloads are saved to a generated filename in the shared
         * download cache and may be deleted by the system at any time to
         * reclaim space.
         *
         * @return this object
         */
        public Request setDestinationUri(Uri uri) {
            mDestinationUri = uri;
            return this;
        }

        /**
         * Set the local destination for the downloaded file to the system cache
         * dir (/cache). This is only available to System apps with the
         * permission
         * {@link android.Manifest.permission#ACCESS_CACHE_FILESYSTEM}.
         * <p/>
         * The downloaded file is not scanned by MediaScanner. But it can be
         * made scannable by calling {@link #allowScanningByMediaScanner()}.
         * <p/>
         * Files downloaded to /cache may be deleted by the system at any time
         * to reclaim space.
         *
         * @return this object
         * @hide
         */
        public Request setDestinationToSystemCache() {
            mUseSystemCache = true;
            return this;
        }

        /**
         * Set the local destination for the downloaded file to a path within
         * the application's external files directory (as returned by
         * {@link android.content.Context#getExternalFilesDir(String)}.
         * <p/>
         * The downloaded file is not scanned by MediaScanner. But it can be
         * made scannable by calling {@link #allowScanningByMediaScanner()}.
         *
         * @param context the {@link android.content.Context} to use in determining the external
         *                files directory
         * @param dirType the directory type to pass to
         *                {@link android.content.Context#getExternalFilesDir(String)}
         * @param subPath the path within the external directory, including the
         *                destination filename
         * @return this object
         */
        public Request setDestinationInExternalFilesDir(Context context,
            String dir, String subPath) {
            File mFile = new File(dir);
            if (!mFile.exists()) {
                mFile.mkdir();
                System.out.println("create dir!!!!!!!!");
            }

            setDestinationFromBase(mFile, subPath);
            return this;
        }

        /**
         * Set the local destination for the downloaded file to a path within
         * the public external storage directory (as returned by
         * {@link android.os.Environment#getExternalStoragePublicDirectory(String)}.
         * <p/>
         * The downloaded file is not scanned by MediaScanner. But it can be
         * made scannable by calling {@link #allowScanningByMediaScanner()}.
         *
         * @param dirType the directory type to pass to
         *                {@link android.os.Environment#getExternalStoragePublicDirectory(String)}
         * @param subPath the path within the external directory, including the
         *                destination filename
         * @return this object
         */
        public Request setDestinationInExternalPublicDir(String dirType,
            String subPath) {
            File file = Environment.getExternalStoragePublicDirectory(dirType);
            if (file.exists()) {
                if (!file.isDirectory()) {
                    throw new IllegalStateException(file.getAbsolutePath()
                        + " already exists and is not a directory");
                }
            } else {
                if (!file.mkdir()) {
                    throw new IllegalStateException(
                        "Unable to create directory: "
                            + file.getAbsolutePath()
                    );
                }
            }
            setDestinationFromBase(file, subPath);
            return this;
        }

        private void setDestinationFromBase(File base, String subPath) {
            if (subPath == null) {
                throw new NullPointerException("subPath cannot be null");
            }
            mDestinationUri = Uri.withAppendedPath(Uri.fromFile(base), subPath);
        }

        /**
         * If the file to be downloaded is to be scanned by MediaScanner, this
         * method should be called before
         * {@link com.ngds.library.downloadcenter.AppDownloadManager#enqueue(com.ngds.library.downloadcenter.AppDownloadManager.Request)} is called.
         */
        public void allowScanningByMediaScanner() {
            mScannable = true;
        }

        /**
         * Add an HTTP header to be included with the download request. The
         * header will be added to the end of the list.
         *
         * @param header HTTP header name
         * @param value  header value
         * @return this object
         * @see <a
         * href="http://www.w3.org/Protocols/rfc2616/rfc2616-sec4.html#sec4.2">HTTP/1.1
         * Message Headers</a>
         */
        public Request addRequestHeader(String header, String value) {
            if (header == null) {
                throw new NullPointerException("header cannot be null");
            }
            if (header.contains(":")) {
                throw new IllegalArgumentException("header may not contain ':'");
            }
            if (value == null) {
                value = "";
            }
            mRequestHeaders.add(Pair.create(header, value));
            return this;
        }

        /**
         * Set the title of this download, to be displayed in notifications (if
         * enabled). If no title is given, a default one will be assigned based
         * on the download filename, once the download starts.
         *
         * @return this object
         */
        public Request setTitle(CharSequence title) {
            mTitle = title;
            return this;
        }

        /**
         * Set a description of this download, to be displayed in notifications
         * (if enabled)
         *
         * @return this object
         */
        public Request setDescription(CharSequence description) {
            mDescription = description;
            return this;
        }

        /**
         * Set the MIME content type of this download. This will override the
         * content type declared in the server's response.
         *
         * @return this object
         * @see <a
         * href="http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.7">HTTP/1.1
         * Media Types</a>
         */
        public Request setMimeType(String mimeType) {
            mMimeType = mimeType;
            return this;
        }


        /**
         * Control whether a system notification is posted by the download
         * manager while this download is running or when it is completed. If
         * enabled, the download manager posts notifications about downloads
         * through the system {@link android.app.NotificationManager}. By
         * default, a notification is shown only when the download is in
         * progress.
         * <p/>
         * It can take the following values: {@link #VISIBILITY_HIDDEN},
         * {@link #VISIBILITY_VISIBLE},
         * {@link #VISIBILITY_VISIBLE_NOTIFY_COMPLETED}.
         * <p/>
         * If set to {@link #VISIBILITY_HIDDEN}, this requires the permission
         * android.permission.DOWNLOAD_WITHOUT_NOTIFICATION.
         *
         * @param visibility the visibility setting value
         * @return this object
         */
        public Request setNotificationVisibility(int visibility) {
            mNotificationVisibility = visibility;
            return this;
        }

        /**
         * Restrict the types of networks over which this download may proceed.
         * By default, all network types are allowed.
         *
         * @param flags any combination of the NETWORK_* bit flags.
         * @return this object
         */
        public Request setAllowedNetworkTypes(int flags) {
            mAllowedNetworkTypes = flags;
            return this;
        }


        /**
         * Set whether this download should be displayed in the system's
         * Downloads UI. True by default.
         *
         * @param isVisible whether to display this download in the Downloads UI
         * @return this object
         */
        public Request setVisibleInDownloadsUi(boolean isVisible) {
            mIsVisibleInDownloadsUi = isVisible;
            return this;
        }

        /**
         * @return ContentValues to be passed to DownloadProvider.insert()
         */
        ContentValues toContentValues(String packageName) {
            ContentValues values = new ContentValues();
            assert mUri != null;
            values.put(Downloads.Impl.COLUMN_URI, mUri.toString());
            values.put(Downloads.Impl.COLUMN_IS_PUBLIC_API, true);
            values.put(Downloads.Impl.COLUMN_NOTIFICATION_PACKAGE, packageName);

            if (mDestinationUri != null) {
                values.put(Downloads.Impl.COLUMN_DESTINATION,
                    Downloads.Impl.DESTINATION_FILE_URI);
                values.put(Downloads.Impl.COLUMN_FILE_NAME_HINT,
                    mDestinationUri.toString());
            } else {
                values.put(
                    Downloads.Impl.COLUMN_DESTINATION,
                    (this.mUseSystemCache) ? Downloads.Impl.DESTINATION_SYSTEMCACHE_PARTITION
                        : Downloads.Impl.DESTINATION_CACHE_PARTITION_PURGEABLE
                );
            }
            // is the file supposed to be media-scannable?
            values.put(Downloads.Impl.COLUMN_MEDIA_SCANNED,
                (mScannable) ? SCANNABLE_VALUE_YES : SCANNABLE_VALUE_NO);

            if (!mRequestHeaders.isEmpty()) {
                encodeHttpHeaders(values);
            }

            putIfNonNull(values, Downloads.Impl.COLUMN_TITLE, mTitle);
            putIfNonNull(values, Downloads.Impl.COLUMN_DESCRIPTION,
                mDescription);
            putIfNonNull(values, Downloads.Impl.COLUMN_MIME_TYPE, mMimeType);

            putIfNonNull(values, Downloads.Impl.COLUMN_IS_START_DIRETLY, mIsStartDirectly);

            values.put(Downloads.Impl.COLUMN_VISIBILITY,
                mNotificationVisibility);
            values.put(Downloads.Impl.COLUMN_ALLOWED_NETWORK_TYPES,
                mAllowedNetworkTypes);
            values.put(Downloads.Impl.COLUMN_IS_VISIBLE_IN_DOWNLOADS_UI,
                mIsVisibleInDownloadsUi);

            return values;
        }

        private void encodeHttpHeaders(ContentValues values) {
            int index = 0;
            for (Pair<String, String> header : mRequestHeaders) {
                String headerString = header.first + ": " + header.second;
                values.put(Downloads.Impl.RequestHeaders.INSERT_KEY_PREFIX
                    + index, headerString);
                index++;
            }
        }

        private void putIfNonNull(ContentValues contentValues, String key,
            Object value) {
            if (value != null) {
                contentValues.put(key, value.toString());
            }
        }
    }


    /**
     * This class may be used to filter download manager queries.
     */
    public static class Query {
        /**
         * Constant for use with {@link #orderBy}
         *
         * @hide
         */
        public static final int ORDER_ASCENDING = 1;

        /**
         * Constant for use with {@link #orderBy}
         *
         * @hide
         */
        public static final int ORDER_DESCENDING = 2;

        private long[] mIds = null;
        private Integer mStatusFlags = null;
        private String[] mUrl = null;
        private String mOrderByColumn = Downloads.Impl.COLUMN_LAST_MODIFICATION;
        private int mOrderDirection = ORDER_DESCENDING;
        private boolean mOnlyIncludeVisibleInDownloadsUi = false;

        /**
         * Include only the downloads with the given IDs.
         *
         * @return this object
         */
        public Query setFilterById(long... ids) {
            mIds = ids;
            return this;
        }

        /**
         * Include only downloads with status matching any the given status
         * flags.
         *
         * @param flags any combination of the STATUS_* bit flags
         * @return this object
         */
        public Query setFilterByStatus(int flags) {
            mStatusFlags = flags;
            return this;
        }

        public Query setFilterByUrl(String... urls) {
            mUrl = urls;
            return this;
        }

        /**
         * Controls whether this query includes downloads not visible in the
         * system's Downloads UI.
         *
         * @param value if true, this query will only include downloads that
         *              should be displayed in the system's Downloads UI; if false
         *              (the default), this query will include both visible and
         *              invisible downloads.
         * @return this object
         */
        public Query setOnlyIncludeVisibleInDownloadsUi(boolean value) {
            mOnlyIncludeVisibleInDownloadsUi = value;
            return this;
        }

        /**
         * Change the sort order of the returned Cursor.
         *
         * @param column    one of the COLUMN_* constants; currently, only
         *                  {@link #COLUMN_LAST_MODIFIED_TIMESTAMP} and
         *                  {@link #COLUMN_TOTAL_SIZE_BYTES} are supported.
         * @param direction either {@link #ORDER_ASCENDING} or
         *                  {@link #ORDER_DESCENDING}
         * @return this object
         * @hide
         */
        public Query orderBy(String column, int direction) {
            if (direction != ORDER_ASCENDING && direction != ORDER_DESCENDING) {
                throw new IllegalArgumentException("Invalid direction: "
                    + direction);
            }

            if (column.equals(COLUMN_LAST_MODIFIED_TIMESTAMP)) {
                mOrderByColumn = Downloads.Impl.COLUMN_LAST_MODIFICATION;
            } else if (column.equals(COLUMN_TOTAL_SIZE_BYTES)) {
                mOrderByColumn = Downloads.Impl.COLUMN_TOTAL_BYTES;
            } else if (column.equals(COLUMN_ID)) {
                mOrderByColumn = COLUMN_ID;
            } else {
                throw new IllegalArgumentException("Cannot order by " + column);
            }
            mOrderDirection = direction;
            return this;
        }

        /**
         * Run this query using the given ContentResolver.
         *
         * @param projection the projection to pass to ContentResolver.query()
         * @return the Cursor returned by ContentResolver.query()
         */
        Cursor runQuery(ContentResolver resolver, String[] projection,
            Uri baseUri) {
            Uri uri = baseUri;
            List<String> selectionParts = new ArrayList<String>();
            String[] selectionArgs = null;

            if (mIds != null) {
                selectionParts.add(getWhereClauseForIds(mIds));
                selectionArgs = getWhereArgsForIds(mIds);
            }
            if (null != mUrl) {
                selectionParts.add(getWhereClauseForUrls(mUrl));
                selectionArgs = getWhereArgsForUrls(mUrl);
            }


            if (mStatusFlags != null) {
                List<String> parts = new ArrayList<String>();
                if ((mStatusFlags & STATUS_PENDING) != 0) {
                    parts.add(statusClause("=", Downloads.Impl.STATUS_PENDING));
                }
                if ((mStatusFlags & STATUS_RUNNING) != 0) {
                    parts.add(statusClause("=", Downloads.Impl.STATUS_RUNNING));
                }
                if ((mStatusFlags & STATUS_PAUSED) != 0) {
                    parts.add(statusClause("=",
                        Downloads.Impl.STATUS_PAUSED_BY_APP));
                    parts.add(statusClause("=",
                        Downloads.Impl.STATUS_WAITING_TO_RETRY));
                    parts.add(statusClause("=",
                        Downloads.Impl.STATUS_WAITING_FOR_NETWORK));
                    parts.add(statusClause("=",
                        Downloads.Impl.STATUS_QUEUED_FOR_WIFI));
                }
                if ((mStatusFlags & STATUS_SUCCESSFUL) != 0) {
                    parts.add(statusClause("=", Downloads.Impl.STATUS_SUCCESS));
                }
                if ((mStatusFlags & STATUS_FAILED) != 0) {
                    parts.add("(" + statusClause(">=", 400) + " AND "
                        + statusClause("<", 600) + ")");
                }
                selectionParts.add(joinStrings(" OR ", parts));
            }

            if (mOnlyIncludeVisibleInDownloadsUi) {
                selectionParts
                    .add(Downloads.Impl.COLUMN_IS_VISIBLE_IN_DOWNLOADS_UI
                        + " != '0'");
            }

            // only return rows which are not marked 'deleted = 1'
            selectionParts.add(Downloads.Impl.COLUMN_DELETED + " != '1'");

            String selection = joinStrings(" AND ", selectionParts);
            String orderDirection = (mOrderDirection == ORDER_ASCENDING ? "ASC"
                : "DESC");
            String orderBy = mOrderByColumn + " " + orderDirection;

            return resolver.query(uri, projection, selection, selectionArgs,
                orderBy);
        }

        private String joinStrings(String joiner, Iterable<String> parts) {
            StringBuilder builder = new StringBuilder();
            boolean first = true;
            for (String part : parts) {
                if (!first) {
                    builder.append(joiner);
                }
                builder.append(part);
                first = false;
            }
            return builder.toString();
        }

        private String statusClause(String operator, int value) {
            return Downloads.Impl.COLUMN_STATUS + operator + "'" + value + "'";
        }
    }


    private ContentResolver mResolver;
    private String mPackageName;
    private Uri mBaseUri = Downloads.Impl.CONTENT_URI;
    static AppDownloadManager mDownloadManager;

    public static AppDownloadManager getDownloadManagerService(Context context) {
        if (mDownloadManager == null) {
            mDownloadManager =
                new AppDownloadManager(context.getContentResolver(), context.getPackageName());
        }
        return mDownloadManager;
    }

    public AppDownloadManager() {
    }

    public AppDownloadManager(ContentResolver resolver, String packageName) {
        mResolver = resolver;
        mPackageName = packageName;
    }

    /**
     * Makes this object access the download provider through /all_downloads
     * URIs rather than /my_downloads URIs, for clients that have permission to
     * do so.
     *
     * @hide
     */
    public void setAccessAllDownloads(boolean accessAllDownloads) {
        if (accessAllDownloads) {
            mBaseUri = Downloads.Impl.ALL_DOWNLOADS_CONTENT_URI;
        } else {
            mBaseUri = Downloads.Impl.CONTENT_URI;
        }
    }

    /**
     * Enqueue a new download. The download will start automatically once the
     * download manager is ready to execute it and connectivity is available.
     *
     * @param request the parameters specifying this download
     * @return an ID for the download, unique across the system. This ID is used
     * to make future calls related to this download.
     */
    public long enqueue(Request request) {


        ContentValues values = request.toContentValues(mPackageName);
        Uri downloadUri = mResolver.insert(Downloads.Impl.CONTENT_URI, values);
        long id = Long.parseLong(downloadUri.getLastPathSegment());
        return id;
    }

    /**
     * Marks the specified download as 'to be deleted'. This is done when a
     * completed download is to be removed but the row was stored without enough
     * info to delete the corresponding metadata from Mediaprovider database.
     * Actual cleanup of this row is done in DownloadService.
     *
     * @param ids the IDs of the downloads to be marked 'deleted'
     * @return the number of downloads actually updated
     * @hide
     */
    public int markRowDeleted(long... ids) {
        if (ids == null || ids.length == 0) {
            // called with nothing to remove!
            throw new IllegalArgumentException(
                "input param 'ids' can't be null");
        }
        ContentValues values = new ContentValues();
        values.put(Downloads.Impl.COLUMN_DELETED, 1);
        // if only one id is passed in, then include it in the uri itself.
        // this will eliminate a full database scan in the download service.
        if (ids.length == 1) {
            return mResolver.update(
                ContentUris.withAppendedId(mBaseUri, ids[0]), values, null,
                null);
        }
        return mResolver.update(mBaseUri, values, getWhereClauseForIds(ids),
            getWhereArgsForIds(ids));
    }

    /**
     * Cancel downloads and remove them from the download manager. Each download
     * will be stopped if it was running, and it will no longer be accessible
     * through the download manager. If there is a downloaded file, partial or
     * complete, it is deleted.
     *
     * @param ids the IDs of the downloads to remove
     * @return the number of downloads actually removed
     */
    public int remove(long... ids) {
        return markRowDeleted(ids);
    }

    /**
     * Query the download manager about downloads that have been requested.
     *
     * @param query parameters specifying filters for this query
     * @return a Cursor over the result set of downloads, with columns
     * consisting of all the COLUMN_* constants.
     */
    public Cursor query(Query query) {
        Cursor underlyingCursor = query.runQuery(mResolver, UNDERLYING_COLUMNS,
            mBaseUri);
        if (underlyingCursor == null) {
            return null;
        }
        return new CursorTranslator(underlyingCursor, mBaseUri);
    }

    /**
     * Open a downloaded file for reading. The download must have completed.
     *
     * @param id the ID of the download
     * @return a read-only {@link android.os.ParcelFileDescriptor}
     * @throws java.io.FileNotFoundException if the destination file does not already exist
     */
    public ParcelFileDescriptor openDownloadedFile(long id)
        throws FileNotFoundException {
        return mResolver.openFileDescriptor(getDownloadUri(id), "r");
    }

    /**
     * Returns {@link android.net.Uri} for the given downloaded file id, if the file is
     * downloaded successfully. otherwise, null is returned.
     * <p/>
     * If the specified downloaded file is in external storage (for example,
     * /sdcard dir), then it is assumed to be safe for anyone to read and the
     * returned {@link android.net.Uri} corresponds to the filepath on sdcard.
     *
     * @param id the id of the downloaded file.
     * @return the {@link android.net.Uri} for the given downloaded file id, if download was
     * successful. null otherwise.
     */
    public Uri getUriForDownloadedFile(long id) {
        // to check if the file is in cache, get its destination from the
        // database
        Query query = new Query().setFilterById(id);
        Cursor cursor = null;
        try {
            cursor = query(query);
            if (cursor == null) {
                return null;
            }
            if (cursor.moveToFirst()) {
                int status = cursor.getInt(cursor
                    .getColumnIndexOrThrow(COLUMN_STATUS));
                if (AppDownloadManager.STATUS_SUCCESSFUL == status) {
                    int indx = cursor
                        .getColumnIndexOrThrow(Downloads.Impl.COLUMN_DESTINATION);
                    int destination = cursor.getInt(indx);
                    // TODO: if we ever add API to DownloadManager to let the
                    // caller specify
                    // non-external storage for a downloaded file, then the
                    // following code
                    // should also check for that destination.
                    if (destination == Downloads.Impl.DESTINATION_CACHE_PARTITION
                        || destination == Downloads.Impl.DESTINATION_SYSTEMCACHE_PARTITION
                        || destination == Downloads.Impl.DESTINATION_CACHE_PARTITION_NOROAMING
                        || destination == Downloads.Impl.DESTINATION_CACHE_PARTITION_PURGEABLE) {
                        // return private uri
                        return ContentUris.withAppendedId(
                            Downloads.Impl.CONTENT_URI, id);
                    } else {
                        // return public uri
                        String path = cursor.getString(cursor
                            .getColumnIndexOrThrow(COLUMN_LOCAL_FILENAME));
                        return Uri.fromFile(new File(path));
                    }
                }
            }
        } finally {
            if (cursor != null) {
                cursor.close();
            }
        }
        // downloaded file not found or its status is not 'successfully
        // completed'
        return null;
    }

    /**
     * Returns {@link android.net.Uri} for the given downloaded file id, if the file is
     * downloaded successfully. otherwise, null is returned.
     * <p/>
     * If the specified downloaded file is in external storage (for example,
     * /sdcard dir), then it is assumed to be safe for anyone to read and the
     * returned {@link android.net.Uri} corresponds to the filepath on sdcard.
     *
     * @param id the id of the downloaded file.
     * @return the {@link android.net.Uri} for the given downloaded file id, if download was
     * successful. null otherwise.
     */
    public String getMimeTypeForDownloadedFile(long id) {
        Query query = new Query().setFilterById(id);
        Cursor cursor = null;
        try {
            cursor = query(query);
            if (cursor == null) {
                return null;
            }
            while (cursor.moveToFirst()) {
                return cursor.getString(cursor
                    .getColumnIndexOrThrow(COLUMN_MEDIA_TYPE));
            }
        } finally {
            if (cursor != null) {
                cursor.close();
            }
        }
        // downloaded file not found or its status is not 'successfully
        // completed'
        return null;
    }

    /**
     * Restart the given downloads, which must have already completed
     * (successfully or not). This method will only work when called from within
     * the download manager's process.
     *
     * @param ids the IDs of the downloads
     * @hide
     */
    public void restartDownload(long... ids) throws IllegalArgumentException {
        Cursor cursor = query(new Query().setFilterById(ids));
        try {
            for (cursor.moveToFirst(); !cursor.isAfterLast(); cursor
                .moveToNext()) {
                int status = cursor
                    .getInt(cursor.getColumnIndex(COLUMN_STATUS));
                if (status != STATUS_SUCCESSFUL && status != STATUS_FAILED) {
                    throw new IllegalArgumentException(
                        "Cannot restart incomplete download: "
                            + cursor.getLong(cursor
                            .getColumnIndex(COLUMN_ID))
                    );
                }
            }
        } finally {
            cursor.close();
        }

        ContentValues values = new ContentValues();
        values.put(Downloads.Impl.COLUMN_CURRENT_BYTES, 0);
        values.put(Downloads.Impl.COLUMN_TOTAL_BYTES, -1);
        values.putNull(Downloads.Impl._DATA);
        values.put(Downloads.Impl.COLUMN_STATUS, Downloads.Impl.STATUS_PENDING);
        mResolver.update(mBaseUri, values, getWhereClauseForIds(ids),
            getWhereArgsForIds(ids));
    }

    /**
     * Returns maximum size, in bytes, of downloads that may go over a mobile
     * connection; or null if there's no limit
     *
     * @param context the {@link android.content.Context} to use for accessing the
     *                {@link android.content.ContentResolver}
     * @return maximum size, in bytes, of downloads that may go over a mobile
     * connection; or null if there's no limit
     */
    public static Long getMaxBytesOverMobile(Context context) {
        try {
            return Settings.Secure.getLong(context.getContentResolver(),
                DOWNLOAD_MAX_BYTES_OVER_MOBILE);
        } catch (SettingNotFoundException exc) {
            return null;
        }
    }

    /**
     * The maximum size, in bytes, of a download that the download manager will
     * transfer over a non-wifi connection.
     *
     * @hide
     */
    public static final String DOWNLOAD_MAX_BYTES_OVER_MOBILE =
        "download_manager_max_bytes_over_mobile";

    /**
     * The recommended maximum size, in bytes, of a download that the download
     * manager should transfer over a non-wifi connection. Over this size, the
     * use will be warned, but will have the option to start the download over
     * the mobile connection anyway.
     *
     * @hide
     */
    public static final String DOWNLOAD_RECOMMENDED_MAX_BYTES_OVER_MOBILE =
        "download_manager_recommended_max_bytes_over_mobile";

    /**
     * Returns recommended maximum size, in bytes, of downloads that may go over
     * a mobile connection; or null if there's no recommended limit. The user
     * will have the option to bypass this limit.
     *
     * @param context the {@link android.content.Context} to use for accessing the
     *                {@link android.content.ContentResolver}
     * @return recommended maximum size, in bytes, of downloads that may go over
     * a mobile connection; or null if there's no recommended limit.
     */
    public static Long getRecommendedMaxBytesOverMobile(Context context) {
        try {
            return Settings.Secure.getLong(context.getContentResolver(),
                DOWNLOAD_RECOMMENDED_MAX_BYTES_OVER_MOBILE);
        } catch (SettingNotFoundException exc) {
            return null;
        }
    }

    /**
     * Adds a file to the downloads database system, so it could appear in
     * Downloads App (and thus become eligible for management by the Downloads
     * App).
     * <p/>
     * It is helpful to make the file scannable by MediaScanner by setting the
     * param isMediaScannerScannable to true. It makes the file visible in media
     * managing applications such as Gallery App, which could be a useful
     * purpose of using this API.
     *
     * @param title                   the title that would appear for this file in Downloads App.
     * @param description             the description that would appear for this file in Downloads
     *                                App.
     * @param isMediaScannerScannable true if the file is to be scanned by MediaScanner. Files
     *                                scanned by MediaScanner appear in the applications used to
     *                                view media (for example, Gallery app).
     * @param mimeType                mimetype of the file.
     * @param path                    absolute pathname to the file. The file should be
     *                                world-readable, so that it can be managed by the Downloads App
     *                                and any other app that is used to read it (for example,
     *                                Gallery app to display the file, if the file contents
     *                                represent a video/image).
     * @param length                  length of the downloaded file
     * @param showNotification        true if a notification is to be sent, false otherwise
     * @return an ID for the download entry added to the downloads app, unique
     * across the system This ID is used to make future calls related to
     * this download.
     */
    public long addCompletedDownload(String title, String description,
        boolean isMediaScannerScannable, String mimeType, String path,
        long length, boolean showNotification) {
        // make sure the input args are non-null/non-zero
        validateArgumentIsNonEmpty("title", title);
        validateArgumentIsNonEmpty("description", description);
        validateArgumentIsNonEmpty("path", path);
        validateArgumentIsNonEmpty("mimeType", mimeType);
        if (length <= 0) {
            throw new IllegalArgumentException(
                " invalid value for param: totalBytes");
        }

        // if there is already an entry with the given path name in
        // downloads.db, return its id
        Request request = new Request(NON_DOWNLOADMANAGER_DOWNLOAD)
            .setTitle(title).setDescription(description)
            .setMimeType(mimeType);
        ContentValues values = request.toContentValues(null);
        values.put(Downloads.Impl.COLUMN_DESTINATION,
            Downloads.Impl.DESTINATION_NON_DOWNLOADMANAGER_DOWNLOAD);
        values.put(Downloads.Impl._DATA, path);
        values.put(Downloads.Impl.COLUMN_STATUS, Downloads.Impl.STATUS_SUCCESS);
        values.put(Downloads.Impl.COLUMN_TOTAL_BYTES, length);
        values.put(Downloads.Impl.COLUMN_MEDIA_SCANNED,
            (isMediaScannerScannable) ? Request.SCANNABLE_VALUE_YES
                : Request.SCANNABLE_VALUE_NO
        );
        values.put(
            Downloads.Impl.COLUMN_VISIBILITY,
            (showNotification) ? Request.VISIBILITY_VISIBLE_NOTIFY_ONLY_COMPLETION
                : Request.VISIBILITY_HIDDEN
        );
        Uri downloadUri = mResolver.insert(Downloads.Impl.CONTENT_URI, values);
        if (downloadUri == null) {
            return -1;
        }
        return Long.parseLong(downloadUri.getLastPathSegment());
    }

    private static final String NON_DOWNLOADMANAGER_DOWNLOAD =
        "non-dwnldmngr-download-dont-retry2download";

    private static void validateArgumentIsNonEmpty(String paramName, String val) {
        if (TextUtils.isEmpty(val)) {
            throw new IllegalArgumentException(paramName + " can't be null");
        }
    }

    /**
     * Get the DownloadProvider URI for the download with the given ID.
     */
    Uri getDownloadUri(long id) {
        return ContentUris.withAppendedId(mBaseUri, id);
    }

    /**
     * Get a parameterized SQL WHERE clause to select a bunch of IDs.
     */
    static String getWhereClauseForIds(long[] ids) {
        StringBuilder whereClause = new StringBuilder();
        whereClause.append("(");
        for (int i = 0; i < ids.length; i++) {
            if (i > 0) {
                whereClause.append("OR ");
            }
            whereClause.append(Downloads.Impl._ID);
            whereClause.append(" = ? ");
        }
        whereClause.append(")");
        return whereClause.toString();
    }

    /**
     * Get the selection args for a clause returned by
     * {@link #getWhereClauseForIds(long[])}.
     */
    static String[] getWhereArgsForIds(long[] ids) {
        String[] whereArgs = new String[ids.length];
        for (int i = 0; i < ids.length; i++) {
            whereArgs[i] = Long.toString(ids[i]);
        }
        return whereArgs;
    }

    /**
     * Get a parameterized SQL WHERE clause to select url.
     */
    static String getWhereClauseForUrls(String[] urls) {
        StringBuilder whereClause = new StringBuilder();
        whereClause.append("(");
        for (int i = 0; i < urls.length; i++) {
            if (i > 0) {
                whereClause.append("OR ");
            }
            whereClause.append(Downloads.Impl.COLUMN_URI);
            whereClause.append(" = ? ");
        }
        whereClause.append(")");
        return whereClause.toString();
    }


    static String[] getWhereArgsForUrls(String[] urls) {
        String[] whereArgs = new String[urls.length];
        for (int i = 0; i < urls.length; i++) {
            whereArgs[i] = urls[i];
        }
        return whereArgs;
    }


    /**
     * This class wraps a cursor returned by DownloadProvider -- the
     * "underlying cursor" -- and presents a different set of columns, those
     * defined in the DownloadManager.COLUMN_* constants. Some columns
     * correspond directly to underlying values while others are computed from
     * underlying data.
     */
    private static class CursorTranslator extends CursorWrapper {
        private Uri mBaseUri;

        public CursorTranslator(Cursor cursor, Uri baseUri) {
            super(cursor);
            mBaseUri = baseUri;
        }

        @Override
        public int getInt(int columnIndex) {
            return (int) getLong(columnIndex);
        }

        @Override
        public long getLong(int columnIndex) {
            if (getColumnName(columnIndex).equals(COLUMN_REASON)) {
                return getReason(super
                    .getInt(getColumnIndex(Downloads.Impl.COLUMN_STATUS)));
            } else if (getColumnName(columnIndex).equals(COLUMN_STATUS)) {
                return translateStatus(super
                    .getInt(getColumnIndex(Downloads.Impl.COLUMN_STATUS)));
            } else {
                return super.getLong(columnIndex);
            }
        }

        @Override
        public String getString(int columnIndex) {
            return (getColumnName(columnIndex).equals(COLUMN_LOCAL_URI)) ? getLocalUri()
                : super.getString(columnIndex);
        }

        private String getLocalUri() {
            long destinationType = getLong(getColumnIndex(Downloads.Impl.COLUMN_DESTINATION));
            if (destinationType == Downloads.Impl.DESTINATION_FILE_URI
                || destinationType == Downloads.Impl.DESTINATION_EXTERNAL
                || destinationType == Downloads.Impl.DESTINATION_NON_DOWNLOADMANAGER_DOWNLOAD) {
                String localPath = getString(getColumnIndex(COLUMN_LOCAL_FILENAME));
                if (localPath == null) {
                    return null;
                }
                return Uri.fromFile(new File(localPath)).toString();
            }

            // return content URI for cache download
            long downloadId = getLong(getColumnIndex(Downloads.Impl._ID));
            return ContentUris.withAppendedId(mBaseUri, downloadId).toString();
        }

        private long getReason(int status) {
            switch (translateStatus(status)) {
                case STATUS_FAILED:
                    return getErrorCode(status);

                case STATUS_PAUSED:
                    return getPausedReason(status);

                default:
                    return 0; // arbitrary value when status is not an error
            }
        }

        private long getPausedReason(int status) {
            switch (status) {
                case Downloads.Impl.STATUS_WAITING_TO_RETRY:
                    return PAUSED_WAITING_TO_RETRY;

                case Downloads.Impl.STATUS_WAITING_FOR_NETWORK:
                    return PAUSED_WAITING_FOR_NETWORK;

                case Downloads.Impl.STATUS_QUEUED_FOR_WIFI:
                    return PAUSED_QUEUED_FOR_WIFI;

                default:
                    return PAUSED_UNKNOWN;
            }
        }

        private long getErrorCode(int status) {
            if ((400 <= status && status < Downloads.Impl.MIN_ARTIFICIAL_ERROR_STATUS)
                || (500 <= status && status < 600)) {
                // HTTP status code
                return status;
            }

            switch (status) {
                case Downloads.Impl.STATUS_FILE_ERROR:
                    return ERROR_FILE_ERROR;

                case Downloads.Impl.STATUS_UNHANDLED_HTTP_CODE:
                case Downloads.Impl.STATUS_UNHANDLED_REDIRECT:
                    return ERROR_UNHANDLED_HTTP_CODE;

                case Downloads.Impl.STATUS_HTTP_DATA_ERROR:
                    return ERROR_HTTP_DATA_ERROR;

                case Downloads.Impl.STATUS_TOO_MANY_REDIRECTS:
                    return ERROR_TOO_MANY_REDIRECTS;

                case Downloads.Impl.STATUS_INSUFFICIENT_SPACE_ERROR:
                    return ERROR_INSUFFICIENT_SPACE;

                case Downloads.Impl.STATUS_DEVICE_NOT_FOUND_ERROR:
                    return ERROR_DEVICE_NOT_FOUND;

                case Downloads.Impl.STATUS_CANNOT_RESUME:
                    return ERROR_CANNOT_RESUME;

                case Downloads.Impl.STATUS_FILE_ALREADY_EXISTS_ERROR:
                    return ERROR_FILE_ALREADY_EXISTS;

                case Downloads.Impl.STATUS_BLOCKED:
                    return ERROR_BLOCKED;

                default:
                    return ERROR_UNKNOWN;
            }
        }

        private int translateStatus(int status) {
            switch (status) {
                case Downloads.Impl.STATUS_PENDING:
                    return STATUS_PENDING;

                case Downloads.Impl.STATUS_RUNNING:
                    return STATUS_RUNNING;

                case Downloads.Impl.STATUS_PAUSED_BY_APP:
                    //                case Downloads.Impl.STATUS_WAITING_TO_RETRY:
                    //                case Downloads.Impl.STATUS_WAITING_FOR_NETWORK:
                    //                case Downloads.Impl.STATUS_QUEUED_FOR_WIFI:
                    return STATUS_PAUSED;

                case Downloads.Impl.STATUS_SUCCESS:
                    return STATUS_SUCCESSFUL;

                case Downloads.Impl.STATUS_WAITING_TO_RETRY:
                case Downloads.Impl.STATUS_WAITING_FOR_NETWORK:
                case Downloads.Impl.STATUS_QUEUED_FOR_WIFI:
                default:
                    assert Downloads.Impl.isStatusError(status);
                    return STATUS_FAILED;
            }
        }
    }

    /**
     * pause download
     *
     * @param ids the IDs of the downloads to be paused
     * @return the number of downloads actually paused
     */
    public int pauseDownload(long... ids) {
        if (ids == null || ids.length == 0) {
            // called with nothing to remove!
            throw new IllegalArgumentException("input param 'ids' can't be null");
        }

        ContentValues values = new ContentValues();
        values.put(Downloads.Impl.COLUMN_CONTROL, Downloads.Impl.CONTROL_PAUSED);
        values.put(Downloads.Impl.COLUMN_STATUS, Downloads.Impl.STATUS_PAUSED_BY_APP);
        if (ids.length == 1) {
            return mResolver.update(ContentUris.withAppendedId(mBaseUri, ids[0]), values,
                null, null);
        }
        return mResolver.update(mBaseUri, values, getWhereClauseForIds(ids),
            getWhereArgsForIds(ids));
    }

    /**
     * resume download
     *
     * @param ids the IDs of the downloads to be resumed
     * @return the number of downloads actually resumed
     */
    public int resumeDownload(long... ids) {
        if (ids == null || ids.length == 0) {
            // called with nothing to remove!
            throw new IllegalArgumentException("input param 'ids' can't be null");
        }

        ContentValues values = new ContentValues();
        values.put(Downloads.Impl.COLUMN_CONTROL, Downloads.Impl.CONTROL_RUN);
        values.put(Downloads.Impl.COLUMN_STATUS, Downloads.Impl.STATUS_RUNNING);
        if (ids.length == 1) {
            return mResolver.update(ContentUris.withAppendedId(mBaseUri, ids[0]), values,
                null, null);
        }
        return mResolver.update(mBaseUri, values, getWhereClauseForIds(ids),
            getWhereArgsForIds(ids));
    }

}
